Water and associated contaminants seep into the ground and travel through a subsurface region known as the vadose zone (a region of unsaturated soil). How the water and associated contaminants move in the vadose zone, to a large degree, determines how much contamination (such as gasoline additives, agricultural chemicals, or buried waste leakage) may end up in a water supply (such as an aquifer). Therefore, gaining an understanding of how the water and associated contaminants move in the vadose zone is valuable for appropriate waste containment. Information regarding the movement of water and associated contaminants in the vadose zone is generally acquired through the use of subsurface probes or similar testing devices. Several apparatus and methods have been used to facilitate such testing and information gathering. Some of these apparatus and methods involve obtaining samples of subsurface liquids, while others test soil moisture or other parameters.
Monitoring and testing to determine the movement of subsurface water and associated contaminants is particularly valuable when dealing with waste disposal sites that contain radiological contaminants or other hazards. However, as described above, placing probes into the subsurface for data collection in such sites has not been feasible, because the placing of such probes would require drilling or coring which would bring contaminated “cuttings” to the surface and would create a pathway through which contaminated emissions may escape. As a result, testing probes have typically been placed in areas around such waste sites. Unfortunately, such probe placement only provides information when the contaminants have already migrated outside of the waste disposal site area. Moreover, at the point when the contaminants have already migrated outside of the waste disposal site area, it is likely that a major contaminant plume already exists in the subsurface soil and aquifer making remediation and containment efforts much more difficult and costly.
In view of the foregoing, it would be highly desirable to provide methods and apparatus which facilitate the installation of subsurface testing instruments in both contaminated and non-contaminated areas, while substantially avoiding these and other shortcomings of prior devices.